package com.lw.sbdemo2.common.utils;

import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.NameValuePair;
import org.apache.http.ParseException;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.entity.UrlEncodedFormEntity;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.client.methods.HttpUriRequest;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.message.BasicNameValuePair;
import org.apache.http.protocol.HTTP;
import org.apache.http.util.EntityUtils;

import java.io.IOException;
import java.io.UnsupportedEncodingException;
import java.util.*;

/**
 * 调用HTTP请求工具类
 *
 * @author LinWang
 * @createTime 2016-12-26
 */
@SuppressWarnings("deprecation")
public class HttpClientUtil {

    public static void main(String[] args) {
        String url = "http://localhost:8081/";
        Map<String, String> userMap = new HashMap<>(16);
        String result = get(url);
        System.out.println(result);
    }

    public static String post(String url, Map<String, String> headers, Map<String, String> params) {
        DefaultHttpClient httpclient = new DefaultHttpClient();
        String body = null;
        HttpPost post = postForm(url, headers, params);

        body = invoke(httpclient, post);

        httpclient.getConnectionManager().shutdown();

        return body;
    }

    public static String get(String url) {
        DefaultHttpClient httpclient = new DefaultHttpClient();
        String body = null;

        HttpGet get = new HttpGet(url);
        body = invoke(httpclient, get);

        httpclient.getConnectionManager().shutdown();

        return body;
    }


    private static String invoke(DefaultHttpClient httpclient,
                                 HttpUriRequest httpost) {

        HttpResponse response = sendRequest(httpclient, httpost);
        String body = paseResponse(response);

        return body;
    }

    private static String paseResponse(HttpResponse response) {
        HttpEntity entity = response.getEntity();

        String body = null;
        try {
            body = EntityUtils.toString(entity);
        } catch (ParseException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }

        return body;
    }

    private static HttpResponse sendRequest(DefaultHttpClient httpclient,
                                            HttpUriRequest httpost) {
        HttpResponse response = null;

        try {
            response = httpclient.execute(httpost);
        } catch (ClientProtocolException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
        return response;
    }

    private static HttpPost postForm(String url, Map<String, String> headers, Map<String, String> params) {

        HttpPost httpost = new HttpPost(url);
        List<NameValuePair> nvps = new ArrayList<NameValuePair>();

        if (params != null) {
            Set<String> keySet = params.keySet();
            for (String key : keySet) {
                nvps.add(new BasicNameValuePair(key, params.get(key)));
            }
        }

        try {
            httpost.setEntity(new UrlEncodedFormEntity(nvps, HTTP.UTF_8));
            if (headers != null) {
                Set<String> keySet = headers.keySet();
                for (String key : keySet) {
                    httpost.addHeader(key, headers.get(key));
                }
            }
        } catch (UnsupportedEncodingException e) {
            e.printStackTrace();
        }

        return httpost;
    }
}
